If that was what came out of the forks, it looks to me like it hasn't be changed in many, many years.
Where it me, I would have simply removed the fork in it's entirety and stripped it down for a real good inspection/cleaning.
HOWEVER, I'd be careful with using ATF for any extended period of time, yes it has cleaning detergents in it, but it may also have ingredients that can cause issues with the top seals.
How many miles on it.
My theory here is this, how much extra wear on the brass bushings has occurred with that extra dirty oil.
Will the bushing wear cause you seal leaks in the near future.